Despite a protracted and unpopular war in Iraq, the Marine Corps is on pace to reach its ambitious troop-expansion goal two years ahead of schedule. That means at least 4,300 more Marines for local bases and possibly more time home between combat deployments.

The Corps' total strength would rise from 175,000 early last year to 202,000. As of last month, it had about 198,000 troops.

The service is expected to achieve the milestone next September – if not before – as long as recruiters are able to ship enough new recruits to boot camps in San Diego and Parris Island, S.C., by then.

A leading defense expert suggested the Marines might have doubled-timed their expansion efforts to beat a review by President-elect Barack Obama, who campaigned on the need to withdraw U.S. troops from Iraq.

“The Marine Corps was worried about an Obama presidency,” said Loren Thompson, chief operating officer of the Lexington Institute, a national-security think tank based in Arlington, Va.

“The 202,000 number was contingent upon Marines staying in Iraq,” he said. “If they don't stay in Iraq, then the 202,000 number is not defensible.”

Marine officials, though, chalked up their figures to other reasons: strong retention among combat veterans, better-than-expected enlistment results and the addition of 500 recruiters in the past two years.

“First-termers are re-enlisting at the highest rate ever, and that's taken a great deal of pressure off our recruiters,” said Maj. Christian Devine, a Marine Corps spokesman. “No one expected the numbers we've seen in re-enlistment.”

The beefed-up force comes with a price.

The Corps' enlistment-bonus program has grown from $66 million in 2007 to almost $90 million this year. About one-third of recruits receive bonuses – averaging $8,400 – often to fill critical skills such as combat arms, intelligence or aviation.

Devine described the incentive as “very small in comparison to other services,” adding that young men and women are joining the Marine Corps for more than economic reasons.

“Our image of a smart, tough, elite warrior continues to resonate with the young people seeking to join the Corps,” he said.

They choose the Marines because they want to challenge themselves, said Gunnery Sgt. David Griffin, who became a recruiter one week after the Sept. 11, 2001, terrorist attacks and now heads the Marine Corps recruiting station in National City.

He said the reasons for enlisting have changed little during his term, although in recent weeks there has been a slight uptick in those citing the faltering economy.

“They're more open to looking at the military because they're worried about their jobs,” Griffin said.

He said quotas have risen gradually enough that recruiters in his office haven't felt pressured to boost numbers or relax standards. Griffin also said he has seen no increase in the number of recruits granted waivers for issues such as criminal convictions or past drug use.

In fact, he said, some recruits rejected for those reasons have come back looking for another chance to enlist. He has had to turn them away.